On Sun, Jan 07, 2007 at 12:58:38AM -0800, H. Peter Anvin wrote: > Willy Tarreau wrote: > > > >At work, we had the same problem on a file server with ext3. We use rsync > >to make backups to a local IDE disk, and we noticed that getdents() took > >about the same time as Peter reports (0.2 to 2 seconds), especially in > >maildir directories. We tried many things to fix it with no result, > >including enabling dirindexes. Finally, we made a full backup, and switched > >over to XFS and the problem totally disappeared. So it seems that the > >filesystem matters a lot here when there are lots of entries in a > >directory, and that ext3 is not suitable for usages with thousands > >of entries in directories with millions of files on disk. I'm not > >certain it would be that easy to try other filesystems on kernel.org > >though :-/ > > > > Changing filesystems would mean about a week of downtime for a server. > It's painful, but it's doable; however, if we get a traffic spike during > that time it'll hurt like hell. > > However, if there is credible reasons to believe XFS will help, I'd be > inclined to try it out. The problem is that I have no sufficient FS knowledge to argument why it helps here. It was a desperate attempt to fix the problem for us and it definitely worked well. Hmmm I'm thinking about something very dirty : would it be possible to reduce the current FS size to get more space to create another FS ? Supposing you create a XX GB/TB XFS after the current ext3, you would be able to mount it in some directories with --bind and slowly switch some parts to it. The problem with this approach is that it will never be 100% converted, but as an experiment it might be worth it, no ? Willy - To unsubscribe from this list: send the line "unsubscribe git" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html